Apparatus and method for audio data/audio-related information transfer

ABSTRACT

A method for transferring audio data and audio-related information includes generating second audio data from first audio data, transmitting second audio data and audio-related information associated with the second audio data, and receiving the second audio data and audio-related information which includes information on a sampling frequency of the first audio data.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for digitallytransferring audio data and audio-related information.

2. Description of the Related Art

As used herein, “audio data” is distinguished from “audio-relatedinformation”. The “audio data” is the information representing theactual sounds to be reproduced. The “audio-related information” isdefined as any information that does not directly represent the actualsounds to be reproduced, e.g., category codes, source numbers, andchannel numbers.

Conventional methods for digitally transferring audio data andaudio-related information are based on, for example, internationalstandards such as IEC60958 and IEC61937.

IEC60958, which is used for transferring 2-channel linear PCM data, isused in a wide range of digital data transfer applications including CDsand DVDs. IEC61937 is used for the transfer of data other than linearPCM data, such as compressed data (e.g., data compressed according tothe MPEG standards). In recent years, IEC61937 is used in applicationswhere the multi-channel audio outputs from a DVD apparatus are utilizedfor reproduction by an external decoder amplifier connected to the DVDapparatus.

The aforementioned conventional methods for transferring audio data andaudio-related information aim at simply reproducing the transferredaudio data.

In recent years, frequencies such as 96 kHz, up to 192 kHz, are adoptedas sampling frequencies for DVDs and the like.

However, the aforementioned conventional transfer standards do notsupport sampling frequencies such as 96 kHz and 192 kHz. Therefore, whena player is connected to an external apparatus, the original audio datais subjected to a down sampling process or the like for converting thesampling frequency to 48 kHz before transfer. In this case, however,there is a problem in that the external apparatus receiving thetransferred data is not aware of the value of the sampling frequency atwhich the original audio data was sampled.

FIG. 5 shows an audio data transfer apparatus 100 as a consumer-usedigital audio apparatus. The audio data transfer apparatus 100 includesan audio data transmitter 101 for transmitting audio data and an audiodata receiver 102 for receiving the transmitted audio data, thetransmitter 101 and the receiver 102 being interconnected via an audiodata transfer interface 103 designed for audio data transfer.

Tables 1 and 2 show transfer conditions for transferring audio data fromthe audio data transmitter 101 in the aforementioned audio data transferapparatus 100.

TABLE 1 Signal processing Sampling Monitoring or date transfer frequencyof frequency at the processing transferred data receiving enddown-sampling sampling frequency sampling frequency after down-samplingafter down-sampling up-sampling sampling frequency sampling frequencyafter up-sampling after up-sampling sampling sampling frequency samplingfrequency conversion after sampling after sampling conversion conversionN times speed original sampling N times transfer frequency 1/N timesspeed original sampling 1/N times transfer frequency

TABLE 2 Signal processing or data transfer processing Monitoring abilitydown-sampling possible up-sampling possible sampling conversion possibleN times speed transfer impossible 1/N times speed transfer impossible

As shown in Table 1, the transfer conditions for the audio data transferapparatus 100 include up-sampling, down-sampling, sampling conversion, Ntimes speed transfer, 1/N times speed transfer, etc., in addition totransferring the original audio data at the originally-intended speed.

Under up-sampling, down-sampling, sampling conversion conditions, thesampling frequency of the transferred audio data differs from that ofthe original audio data. However, the audio-related information which istransferred In the conventional audio data transfer apparatus 100 doesnot include information concerning the sampling frequency of theoriginal audio data. As a result, there is a problem in that the audiodata receiver 102 cannot obtain any information concerning the samplingfrequency of the original audio data.

Under conditions where audio data is transferred at an N times transferspeed or a 1/N times transfer speed, the sampling frequency of theoriginal audio data is retained; however, the audio data receiver 102cannot monitor the transferred data as it is (see Table 2). In order toproperly monitor the audio data transferred under N times transfer or1/N times transfer conditions, it is necessary to reproduce the audiodata at an N times or 1/N times speed, or to reproduce the audio data atthe sampling frequency of the original audio data while storing thetransferred audio data in large memories. In the case of non-PCM data,subjecting the transferred data to a decoding process which does notinvolve some special measures would result in the audio informationbeing reproduced with unwanted interruptions because the audio datareceiver 102 often cannot perform the decoding process in time.

FIG. 6 illustrates an example of a conventional audio data/audio-relatedinformation recording format 300. As shown in FIG. 6, the conventionalaudio data/audio-related information recording format 300 contains noinformation indicating the sampling frequency of the original audio dataor no information indicating the transfer speed of the transferred audiodata. Hence, it is impossible for the audio data receiver 102 to detectthe sampling frequency of the original audio data or the transfer speedof the transferred audio data.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided amethod for transferring audio data and audio-related information,comprising: a generation step of generating second audio data from firstaudio data; a transmission step of transmitting the second audio dataand audio-related information associated with the second audio data; anda reception step of receiving the second audio data and theaudio-related information, wherein the audio-related informationincludes information representing a sampling frequency of the firstaudio data.

In one embodiment of the invention, the transmission step comprises aconversion step of converting the sampling frequency of the first audiodata into a sampling frequency which is suitable for reproduction at thereception step.

In another embodiment of the invention, the conversion step comprises adown-sampling.

In still another embodiment of the invention, the conversion stepcomprises an up-sampling.

In still another embodiment of the invention, the conversion stepcomprises a sampling conversion.

In still another embodiment of the invention, the reception stepcomprises displaying the sampling frequency of the first audio data on adisplay.

Alternatively, there is provided a method for transferring audio dataand audio-related information, comprising: a transmission step oftransmitting the audio data and audio-related information associatedwith the audio data; and a reception step of receiving the audio dataand the audio-related information, wherein the audio-related informationincludes monitor information indicating whether or not the audio data iscapable of being monitored in the reception step.

In one embodiment of the invention, the reception step comprisesdisplaying the monitor information on a display.

In another embodiment of the invention, the method further comprises amuting step of muting the audio data if the monitor informationindicates that the audio data is not capable of being monitored in thereception step.

Alternatively, there is provided a method for transferring audio dataand audio-related information, comprising: a transmission step oftransmitting the audio data and audio-related information associatedwith the audio data; and a reception stop of receiving the audio dataand the audio-related information, wherein the audio-related informationincludes information representing a transfer speed of the audio data.

In one embodiment of the invention, the reception step comprisesdisplaying the transfer speed on a display.

According to another aspect of the present invention, there is providedan audio data/audio-related information transfer apparatus fortransferring audio data and audio-related information, comprising: atransmitter for transmitting second audio data and audio-relatedinformation associated with the second audio data, the second audio databeing generated from first audio data; and a receiver for receiving thesecond audio data and the audio-related information, wherein theaudio-related information includes information representing a samplingfrequency of the first audio data.

In one embodiment of the invention, the transmitter converts thesampling frequency of the first audio data into a sampling frequencywhich is suitable for reproduction by the receiver.

In another embodiment of the invention, wherein the transmitter performsa down-sampling for the sampling frequency of the first audio data.

In still another embodiment of the invention, the transmitter performsan up-sampling for the sampling frequency of the first audio data.

In still another embodiment of the invention, the transmitter performs asampling conversion for the sampling frequency of the first audio data.

In still another embodiment of the invention, the receiver comprises adisplay for displaying the sampling frequency of the first audio data.

Alternatively, there is provided an audio data/audio-related informationtransfer apparatus for transferring audio data and audio-relatedinformation, comprising: a transmitter for transmitting audio data andaudio-related information associated with the audio data; and a receiverfor receiving the audio data and the audio-related information, whereinthe audio-related information includes monitor information indicatingwhether or not the audio data is capable of being monitored by thereceiver.

In one embodiment of the invention, the receiver comprises a display fordisplaying the monitor information.

In another embodiment of the invention, the audio data is muted if themonitor information indicates that the audio data is not capable ofbeing monitored by the receiver.

Alternatively, there is provided an audio data/audio-related informationtransfer apparatus for transferring audio data and audio-relatedinformation, comprising: a transmitter for transmitting audio data andaudio-related information associated with the audio data; and a receiverfor receiving the audio data and the audio-related information, whereinthe audio-related information includes information representing atransfer speed of the audio data.

In one embodiment of the invention, the receiver comprises a display fordisplaying the transfer speed.

According to another aspect of the present invention, there is provideda transmitter for transmitting second audio data and audio-relatedinformation associated with the second audio data, the second audio databeing generated from first audio data, wherein the audio-relatedinformation includes information representing a sampling frequency ofthe first audio data.

In one embodiment of the invention, the transmitter converts thesampling frequency of the first audio data into a sampling frequencywhich is suitable for reproduction by the receiver.

In another embodiment of the invention, the transmitter performs adown-sampling for the sampling frequency of the first audio data.

In still another embodiment of the invention, the transmitter performsan up-sampling for the sampling frequency of the first audio data.

In still another embodiment of the invention, the transmitter performs asampling conversion for the sampling frequency of the first audio data.

According to another aspect of the present invention, there is provideda transmitter for transmitting audio data and audio-related informationassociated with the audio data, wherein the audio-related informationincludes monitor information indicating whether or not the audio data iscapable of being monitored by the receiver.

Alternatively, there is provided a transmitter for transmitting audiodata and audio-related information associated with the audio data,wherein the audio-related information includes information representinga transfer speed of the audio data.

According to another aspect of the present invention, there is provideda receiver for receiving second audio data and audio-related informationassociated with the second audio data, the second audio data beinggenerated from first audio data and transmitted from a transmitter,wherein the audio-related information includes information representinga sampling frequency of the first audio data.

In one embodiment of the invention, the receiver comprises a display fordisplaying the sampling frequency of the first audio data.

Alternatively, there is provided a receiver for receiving audio data andaudio-related information associated with the audio data, wherein theaudio-related information includes monitor information Indicatingwhether or not the audio data is capable of being monitored by thereceiver.

In one embodiment of the invention, the receiver comprises a display fordisplaying the monitor information.

In another embodiment of the invention, the audio data is muted if themonitor information indicates that the audio data is not capable ofbeing monitored by the receiver.

Alternatively, there is provided a receiver for receiving audio data andaudio-related information associated with the audio data, the audio databeing transmitted from a transmitter, wherein the audio-relatedinformation includes information representing a sampling frequency ofthe first audio data.

In one embodiment of the invention, the receiver comprises a display fordisplaying the transfer speed.

Thus, the invention described herein makes possible the advantage ofproviding a method and apparatus for performing digital transfer ofaudio data which involves concurrently transferring informationindicating a sampling frequency, monitoring ability, and a transferspeed of audio data, thereby enabling a mode of audio reproduction whichis in accordance with the particular audio data that is beingtransferred.

This and other advantages of the present invention will become apparentto those skilled in the art upon reading and understanding the followingdetailed description with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an audio data transfer apparatusaccording to an example of the present invention.

FIG. 2 is a diagram illustrating an audio data/audio-related informationrecording format according to an example of the present invention.

FIG. 3 is a flowchart illustrating a flow of steps performed duringoriginal audio data sampling frequency information processing accordingto an example of the present invention.

FIG. 4 is a flowchart illustrating a flow of steps during monitorinformation processing according to an example of the present invention.

FIG. 5 In a block diagram illustrating a conventional audio datatransfer apparatus.

FIG. 6 is a diagram illustrating a conventional audio data/audio-relatedinformation recording format.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described with respect to an audio datatransfer method in accordance with the IEC 60958 or IEC61937 transferstandards, with reference to the accompanying figures.

As for the details of the IEC 60958 and IEC61937 transfer standards, seeInterface for Non-linear PCM Encoded Audio Bitstreams Applying IEC61937,for example.

FIG. 1 illustrates an audio data transfer apparatus 10 according to anexample of the present invention. The audio data transfer apparatus 10includes an audio data transmitter 1 for transmitting audio data and anaudio data receiver 2 for receiving the transmitted audio data, theaudio data transmitter 1 and the audio data receiver 2 beinginterconnected via an audio data transfer interface 3 designed for audiodata transfer. The audio data transmitter 1 may be a DVD player or a settop box (STB), for example. The audio data receiver 2 may be an AVdecoder or a minidisk apparatus, for example. The audio data transferinterface 3 may be a conductive cable or an optical fiber, for example.

In accordance with the audio data transfer apparatus 10, audio data isfirst analyzed by a digital audio data attribute analysis section 11.Then, a digital audio data generation section 12 adds appropriateaudio-related information to the audio data (described below).Thereafter, the audio data is modulated by a digital audio datamodulation section 13, and output to the audio data transfer interface 3so as to be transferred to the audio data receiver 2.

FIG. 2 illustrates an audio data/audio-related information recordingformat 200 according to an example of the present invention.

In the audio data/audio-related information recording format 200 shownin FIG. 2, sampling frequency data of the original audio data areassigned in a region 201 spanning the 36th to 39th bits. Table 3 showsthe correspondence between the sampling frequency of the original audiodata and bit information.

TABLE 3 Sampling frequency data of original audio data bit 36 (LSB) -bit 39 (MSB) sampling frequency “0000” 44.1 kHz   “0001” 22.05 kHz  “0010” 88.2 kHz   “0100” 48 kHz “0101” 24 kHz “0100” 96 kHz “1100” 32kHz “1101” 16 kHz “1110” 64 kHz others undefined

In Table 3, nine sampling frequency values are assigned as the samplingfrequency for original audio data: sampling frequencies which arecurrently in common use (i.e., 32 kHz, 44.1 kHz, and 48 kHz);frequencies twice those values (i.e., 64 kHz, 88.2 kHz, and 96 kHz), andfrequencies half those values (i.e., 16 kHz, 22.05 kHz, and 24 kHz).

Since the audio data/audio-related information recording format 200(FIG. 2) includes information representing the sampling frequency of theoriginal audio data as illustrated in Table 3, it is possible for theaudio data receiver 2 to detect the sampling frequency of the originalaudio data even in the case where the audio data to be transferred aredown-sampled from the sampling frequencies 96 kHz and 88.2 kHz, whichare adopted by the DVD audio standards. Moreover, the audiodata/audio-related information recording format 200 (FIG. 2) alsosupports half-rate frequencies of the MPEG2 frequencies, which areadopted by digital satellite broadcast. Even in the case where the audiodata to be transferred are up-sampled from such frequencies, it ispossible for the audio data receiver 2 to detect the audio-relatedinformation associated with the original audio data.

In the audio data/audio-related information recording format 200 (FIG.2), monitor information is assigned in a region 202 at bit 30. Forexample, the monitor information can be expressed by one bit as shown inTable 4.

TABLE 4 Examples of monitor bits bit 30 Monitoring ability “1” possible“0” impossible

The audio data transmitter 1 sets bit 30 to “1” if it is possible tomonitor the audio data, and sets bit 30 to “0” if monitoring ability isnot guaranteed (e.g., if it is impossible to monitor the audio data).

Furthermore, in the audio data/audio-related information recordingformat 200 shown in FIG. 2, transfer speed information is assigned in aregion 203 spanning the 32nd to 35th bits. The transfer speedinformation may be expressed by four bits as shown in Table 5, forexample.

TABLE 5 bit 32 (LSB) - bit 35 (MSB) transfer speed “0000” 4 times “0001”2 times “0010” 1 time “0100” ½ times “0101” ¼ times

Since the audio data/audio-related information recording format 200(FIG. 2) includes information representing the transfer speedinformation as illustrated in Table 5, it is possible for the audio datareceiver 2 to detect the transfer speed of audio data even in the casewhere the audio data is transferred at an N times or 1/N times speed. Inthe case where the audio data receiver 2 includes a data processingmeans which is capable of reproducing audio data at varying speeds, itis possible to vary the reproduction speed of the received audio data onthe basis of the detected transfer speed information.

Although Table 5 illustrates 4 times to ¼ times transfer speeds, thepresent invention is applicable to any transfer speed.

Referring back to FIG. 1, the audio data, as well as audio-relatedinformation including the aforementioned additional information (e.g.,sampling frequency information and transfer speed information), istransferred to the audio data receiver 2 in accordance with the audiodata transfer apparatus 10.

In the audio data receiver 2, the received audio data and audio-relatedinformation in demodulated by a digital audio data demodulation section21, and the audio-related information is analyzed by an additionalinformation analysis section 22. Then, after the audio data is processedby a data processing section 23, the audio data is converted into ananalog signal by a D/A converter section 24 for output. A display datageneration section 25 generates display data based on the audio-relatedinformation, which is displayed on a display 26.

FIG. 3 is a flowchart showing a flow of steps for a processing of thesampling frequency information of original audio data which is performedby the audio data receiver 2.

At Step 32, audio-related information including the sampling frequencyinformation of original audio data to read by an additional informationanalysis section 22 of the audio data receiver 2. Next, at Step 33, theadditional information analysis section 22 looks up in Table 3 the bitinformation representing the sampling frequency of the original audiodata that has been read, thereby detecting the sampling frequency of theoriginal audio data. At Step 34, the display data generation section 25displays the detected sampling frequency of the original audio data onthe display 26.

FIG. 4 is a flowchart showing the monitor information processingperformed in the audio data receiver 2. Specifically, FIG. 4 illustratesmonitor information processing performed in the case where theaudio-related information does not include transfer speed information,or where the audio data receiver 2 does not include a data processingmeans which is capable of reproducing audio data at varying speeds.

At Step 42, audio-related information including the monitor informationof original audio data is read by the additional information analysissection 22 of the audio data receiver 2. Next, at Step 43, theadditional information analysis section 22 detects or determines whetheror not the monitor bit (e.g., bit 30) is “1”, if the monitor bit is “1”,it is possible to monitor the audio data, so that the transferred datais subjected to appropriate signal processing at the data processingsection 23 and the D/A converter section 24, and thereafter output asaudio data at step 44. Next, at Step 46, the display 26 displaysinformation indicating that the audio data can be monitored or in beingmonitored.

On the other hand, in the case where the audio data is transferred at anincreased speed (N times speed) or at a decreased speed (1/N timesspeed), it is impossible to detect what multiples of the originalfrequency the data is being transferred at. In such cases, the audiodata transmitter 1 transmits “0” as the monitor bit to indicate that theaudio data cannot be monitored. When the monitor information indicatingthat monitoring is impossible is read by the additional informationanalysis section 22 in the audio data receiver 2, the audio output ismuted at Step 45, and the display 26 displays information indicatingthat the audio data cannot be monitored or is being muted at Step 49.

In the case where the audio-related information includes transfer speedinformation, the transfer speed information is analyzed by theadditional information analysis section 22, and the transfer speed isdisplayed on the display 26.

In the case where the audio data receiver 2 includes a data processingmeans which is capable of reproducing audio data at varying speeds, thespeed of the audio data is changed based on the detected transfer speedinformation, and the audio data is reproduced at the changed speed.

The present invention has been described above with respect to certainembodiments. The sampling frequency information, the monitorinformation, and the transfer speed information of the original audiodata may all be included in the audio data/audio-related informationrecording format 200. Alternatively, each type of information may beselectively included depending on the needs of the particularapplication. For example, the audio data/audio-related informationrecording format 200 may only include the sampling frequency informationof the original audio data.

The audio data/audio-related information recording format 200 describedabove is only illustrative. Any other format may be employed as theaudio data/audio-related information recording format 200.

Although the audio data transfer according to the above example of thepresent invention is achieved via an audio data transfer interface 3,audio data may be transferred by any other transfer means that iscapable of transferring digital information. For example, it is possibleto transfer audio data via a radio transmission/reception means.

The present invention is applicable not only to the IEC 60958 andIEC61937 transfer standards but also any digital data transferstandards, e.g., IEEE 1394, which is a set of audio video data transferstandards to be enforced in future.

As described above, according to the present invention, an audio datatransmitter adds, to audio data to be transferred, informationindicating a sampling frequency of the original audio data, monitoringability (indicating whether or not it is possible to monitor thetransferred audio data at an audio data receiver), and a transfer speedof audio data. As a result, various information concerning thetransferred data can be detected by the audio data receiver. Thisenables a mode of audio reproduction which is in accordance with theparticular audio data that is being transferred.

Various other modifications will be apparent to and can be readily madeby those skilled in the art without departing from the scope and spiritof this invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the description as set forthherein, but rather that the claims be broadly construed.

What is claimed is:
 1. A method for transferring audio data andaudio-related information, comprising: a generation step of generatingsecond audio data from first audio data; a transmission step oftransmitting the second audio data and audio-related informationassociated with the second audio data; and a reception step of receivingthe second audio data and the audio-related information, wherein theaudio-related information includes information representing a samplingfrequency of the first audio data.
 2. A method according to claim 1,wherein the transmission step comprises a conversion step of convertingthe sampling frequency of the first audio data into a sampling frequencywhich is suitable for reproduction at the reception step.
 3. A methodaccording to claim 2, wherein the conversion step comprises adown-sampling.
 4. A method according to claim 2, wherein the conversionstop comprises an up-sampling.
 5. A method according to claim 2, whereinthe conversion step comprises a sampling conversion.
 6. A methodaccording to claim 1, wherein the reception step comprises displayingthe sampling frequency of the first audio data on a display.
 7. A methodfor transferring audio data and audio-related information, comprising: atransmission step of transmitting the audio data and audio-relatedinformation associated with the audio data; and a reception step ofreceiving the audio data and the audio-related information, wherein theaudio-related information includes monitor information indicatingwhether or not the audio data is capable of being monitored in thereception step.
 8. A method according to claim 7, wherein the receptionstep comprises displaying the monitor information on a display.
 9. Amethod according to claim 7, further comprising a muting step of mutingthe audio data if the monitor information indicates that the audio datais not capable of being monitored in the reception step.
 10. A methodfor transferring audio data and audio-related information, comprising: atransmission step of transmitting the audio data and audio-relatedinformation associated with the audio data: and a reception step ofreceiving the audio data and the audio-related information, wherein theaudio-related information includes information representing a transferspeed of the audio data.
 11. A method according to claim 10, wherein thereception step comprises displaying the transfer speed on a display. 12.A audio data/audio-related information transfer apparatus fortransferring audio data and audio-related information, comprising: atransmitter for transmitting second audio data and audio-relatedinformation associated with the second audio data, the second audio databeing generated from first audio data; and a receiver for receiving thesecond audio data and the audio-related information, wherein theaudio-related information includes information representing a samplingfrequency of the first audio data.
 13. A audio data/audio-relatedinformation transfer apparatus according to claim 12, wherein thetransmitter converts the sampling frequency of the first audio data intoa sampling frequency which is suitable for reproduction by the receiver.14. A audio data/audio-related information transfer apparatus accordingto claim 13, wherein the transmitter performs a down-sampling for thesampling frequency of the first audio data.
 15. A audiodata/audio-related information transfer apparatus according to claim 13,wherein the transmitter performs an up-sampling for the samplingfrequency of the first audio data.
 16. A audio data/audio-relatedinformation transfer apparatus according to claim 13, wherein thetransmitter performs a sampling conversion for the sampling frequency ofthe first audio data.
 17. A audio data/audio-related informationtransfer apparatus according to claim 12, wherein the receiver comprisesa display for displaying the sampling frequency of the first audio data.18. A audio data/audio-related information transfer apparatus fortransferring audio data and audio-related information, comprising: atransmitter for transmitting audio data and audio-related informationassociated with the audio data; and a receiver for receiving the audiodata and the audio-related information, wherein the audio-relatedinformation includes monitor information indicating whether or not theaudio data is capable of being monitored by the receiver.
 19. A audiodata/audio-related information transfer apparatus according to claim 18,wherein the receiver comprises a display for displaying the monitorinformation.
 20. A audio data/audio-related information transferapparatus according to claim 18, wherein the audio data is muted if themonitor information indicates that the audio data is not capable ofbeing monitored by the receiver.
 21. A audio data/audio-relatedinformation transfer apparatus for transferring audio data andaudio-related information, comprising: a transmitter for transmittingaudio data and audio-related information associated with the audio data;and a receiver for receiving the audio data and the audio-relatedinformation, wherein the audio-related information includes informationrepresenting a transfer speed of the audio data.
 22. A audiodata/audio-related information transfer apparatus according to claim 21,wherein the receiver comprises a display for displaying the transferspeed.
 23. A transmitter for transmitting second audio data andaudio-related information associated with the second audio data, thesecond audio data being generated from first audio data, wherein theaudio-related information includes information representing a samplingfrequency of the first audio data.
 24. A transmitter according to claim23, wherein the transmitter converts the sampling frequency of the firstaudio data into a sampling frequency which is suitable for reproductionby the receiver.
 25. A transmitter according to claim 24, wherein thetransmitter performs a down-sampling for the sampling frequency of thefirst audio data.
 26. A transmitter according to claim 24, wherein thetransmitter performs an up-sampling for the sampling frequency of thefirst audio data.
 27. A transmitter according to claim 24, wherein thetransmitter performs a sampling conversion for the sampling frequency ofthe first audio data.